JP4253306B2 - Photosensitive paste and fired product pattern formed using the same - Google Patents

Description

  The present invention is a photosensitive paste that is useful for forming fine barrier rib patterns, dielectric patterns, electrode patterns, and black matrix patterns of a plasma display panel (hereinafter abbreviated as PDP) and has excellent storage stability, And a fired product pattern formed using the same.

The PDP is a flat display that displays images and information using light emission by plasma discharge, and is classified into a DC type and an AC type according to a panel structure and a driving method. The principle of color display by this PDP is that plasma discharge is generated in a cell space (discharge space) between opposing electrodes formed on the front glass substrate and the back glass substrate separated by ribs (partition walls), and each cell The phosphor formed on the inner surface of the rear glass substrate is excited by ultraviolet rays generated by the discharge of a gas such as He or Xe enclosed in the space to generate visible light of the three primary colors.
Hereinafter, it will be briefly described with reference to the accompanying drawings.

FIG. 1 partially shows an example of the structure of a surface discharge PDP having a full color display and a three-electrode structure. On the lower surface of the front glass substrate 1, a large number of a pair of display electrodes 2a and 2b, each consisting of a transparent electrode 3a or 3b for discharging and a bus electrode 4a or 4b for lowering the line resistance of the transparent electrode, at a predetermined pitch. It is lined up. On these display electrodes 2a and 2b, a transparent dielectric layer 5 (low melting point glass) for accumulating charges is formed by printing and baking, and a protective layer (MgO) 6 is deposited thereon. . The protective layer 6 has a role of protecting the display electrode, maintaining a discharge state, and the like. On the other hand, on the rear glass substrate 11, striped ribs (partitions) 12 partitioning the discharge space and a plurality of address electrodes (data electrodes) 13 arranged in each discharge space are arranged in a predetermined pitch. Yes. In addition, on the inner surface of each discharge space, phosphor films of three colors of red (14a), blue (14b), and green (14c) are regularly arranged, and in full color display, as described above, red, blue The three primary color phosphor films 14a, 14b, and 14c constitute one pixel.
In the PDP having the above structure, an alternating pulse voltage is applied between the pair of display electrodes 2a and 2b to cause discharge between the electrodes on the same substrate.
In the PDP having the above structure, ultraviolet light generated by discharge excites the phosphor films 14a, 14b, and 14c of the back substrate 11, and the generated visible light is viewed through the transparent electrodes 3a and 3b of the front substrate 1. It has become.

In recent years, in a PDP having such a structure, higher density and higher definition are required in pattern processing in order to improve image quality. Therefore, patterning by photolithography has been performed. In patterning by a photolithography method, alkali development is generally used. Therefore, an organic polymer compound containing a carboxyl group is used in a photosensitive paste.
However, when a powder containing a polyvalent metal such as glass powder or ceramic powder or an oxide thereof is added to the organic polymer compound containing a carboxyl group as described above in order to prepare a photosensitive paste, such a powder The polyvalent ions eluted from the carboxylic acid groups of the organic polymer compound are ionically cross-linked to form a three-dimensional network, thereby causing thickening and gelation. Further, when the acid value or molecular weight of the resin is large, the gelation speed tends to increase.

Therefore, as a method for preventing gelation, for example, it has been proposed to contain a compound having a carboxyl group in a photosensitive paste as a gelation inhibitor (see Patent Document 1).
However, this method only slightly increases the time until the photosensitive paste is gelled, and since the thickening is large, the practical difficulty of the photosensitive paste has not been substantially eliminated. It is.

In addition, a method of suppressing gelation by including a compound having an amide structure such as stearamide has been proposed (see Patent Document 2). However, even when stearamide is used, the increase in viscosity of the photosensitive paste is so large that it is not suitable for practical use.
JP-A-9-222723 (Claims) JP 2001-155543 A (Claims)

  The present invention has been made in order to solve such problems of the prior art, and its main purpose is to form fine barrier rib patterns, dielectric patterns, electrode patterns, and black matrix patterns of plasma display panels. Another object of the present invention is to provide a photosensitive paste that is useful for the purpose of suppressing the increase in viscosity and gelation and has excellent storage stability, and a fired product pattern formed using the same.

In order to achieve the above object, basic aspects of the photosensitive paste of the present invention include (A) inorganic fine particles excluding boric acid, (B) a carboxyl group-containing resin, (C) a photopolymerizable monomer, (D) It contains a photopolymerization initiator, (E) boric acid having an average particle size (D ₅₀ ) of 20 μm or less, and (F) a hydrophobic solvent. As a more preferred aspect, the photosensitive paste further comprises (G) a polyhydric alcohol.
Furthermore, according to the present invention, a fired product pattern such as a partition pattern, a dielectric pattern, an electrode pattern, and a black matrix pattern obtained by using such a photosensitive paste is provided.

The photosensitive paste of the present invention uses a fine powder boric acid having an average particle size (D ₅₀ ) of 20 μm or less as a stabilizer, and further uses a hydrophobic solvent that prevents the influence of moisture, thereby providing a photosensitive paste having excellent storage stability. Can be provided.
Furthermore, by using a polyhydric alcohol, the acidity of boric acid is improved, and even when a carboxyl group-containing resin having a large acid value or molecular weight is used, a photosensitive paste having excellent stability can be provided.
Thus, by using a photosensitive paste with excellent storage stability, gelation during transportation and storage is reduced, and it is possible to contribute to improving the quality of the PDP produced by this photosensitive paste. Can contribute to down.

The photosensitive paste of the present invention comprises (A) inorganic fine particles excluding boric acid, (B) carboxyl group-containing resin, (C) photopolymerizable monomer, (D) photopolymerization initiator, (E) average particle size (D ₅₀ ) Containing boric acid of 20 μm or less, and (F) a hydrophobic solvent, using boric acid (E) with an average particle size (D ₅₀ ) of 20 μm or less as a stabilizer, and further hydrophobic to prevent the influence of moisture It is characterized in that an organic solvent (F) is used.
The average particle size (D ₅₀ ) is a value indicating the particle diameter when the integrated value of the number of particles is 50% of the total number of particles in the particle size distribution.

Hereinafter, each component of the photosensitive paste of the present invention will be described.
As the inorganic fine particles (A) excluding boric acid, known and commonly used inorganic fine particles can be used, and in particular, at least one selected from the group consisting of glass fine particles, black pigments, and conductive powders is preferably used. it can.
The glass fine particles include, as a main component, glass having a glass transition point (Tg) of 300 to 500 ° C. and a glass softening point (Ts) of 400 to 600 ° C., for example, lead oxide, bismuth oxide, zinc oxide, or lithium oxide. Glass to be used can be suitably used. From the viewpoint of resolution, it is preferable to use glass powder having an average particle size of 10 μm or less, preferably 5 μm or less.

  In addition, the black pigment is used when black is required for the firing pattern, and is made of one or more metal oxides such as Co, Ni, Cu, Fe, Mn, Al, Ru, La, and Sr. A black pigment can be added. It is desirable to use fine particles having an average particle diameter of 2 μm or less, preferably 0.1 to 1 μm. This is because if the average particle diameter is smaller than 2 μm, a dense fired film can be formed without impairing adhesion and the like even with a small amount of addition, and sufficient blackness can be obtained. On the other hand, when the average particle diameter of the black pigment is larger than 2 μm, the denseness of the fired film is deteriorated, and the blackness is easily lowered. On the other hand, if the thickness is smaller than 0.1 μm, the hiding power is lowered and a transparent feeling may appear.

  As such a black pigment, a slurry previously prepared can be used. In this case, it is desirable to use the same type of solvent as that used in the paste in order to prevent solvent shock. The pigment concentration in the slurry can be arbitrarily selected, but is preferably 50 to 80% in consideration of workability and the like.

Examples of the conductive powder include metal powders such as silver (Ag), gold (Au), nickel (Ni), copper (Cu), aluminum (Al), tin (Sn), platinum (Pt), and ruthenium (Ru). In addition to simple substances and alloys thereof, tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), ITO (Indium Tin Oxide), ruthenium oxide (RuO ₂ ), and the like can be used. These can be used alone or as a mixed powder of two or more.

  Various shapes such as a spherical shape, a flake shape, and a dentlite shape can be used as the conductive powder, but it is preferable to use a spherical shape in consideration of optical characteristics and dispersibility. The average particle diameter is preferably 10 μm or less, more preferably 5 μm or less from the viewpoint of the line shape.

  An appropriate proportion of the conductive powder is 50 to 2000 parts by mass when the total amount of paste components other than the conductive powder is 100 parts by mass. When the blending amount of the conductive powder is less than 50 parts by mass, the conductor circuit line width shrinkage or disconnection tends to occur. On the other hand, when the blending amount exceeds 2000 parts by mass, the light transmission is impaired, and the composition is sufficient. It is difficult to obtain a good photocurability. Furthermore, in order to improve the strength of the film after firing and the adhesion to the substrate, the glass fine particles as described above can be added at a ratio of 1 to 30 parts by mass per 100 parts by mass of the metal powder.

As other inorganic fine particles, silica powder, particularly synthetic amorphous silica fine powder, can be used as long as it does not adversely affect the fired product pattern.
Specific examples of the synthetic amorphous silica fine powder include AEROSIL (registered trademark) 50, 130, 200, 200V, 200CF, 200FAD, 300, 300CF, 380, OX50, TT600, MOX80, MOX170, manufactured by Nippon Aerosil Co., Ltd. NIPsil (registered trademark) AQ, AQ-S, VN3, LP, L300, N-300A, ER-R, ER, RS-150, ES, NS, NS-T, NS -P, NS-KR, NS-K, NA, KQ, KM, DS and the like can be mentioned, and these can be used alone or in combination of two or more. Among these, those having a primary particle diameter of 5 to 50 nm and a specific surface area of 50 to 500 m ² / g are preferable.

  Next, as the carboxyl group-containing resin (B), a known and commonly used resin having a free carboxyl group in the molecule can be used, and two or more in one molecule in the carboxyl group-containing resin (B). A carboxyl group-containing photosensitive resin (B ′) having an ethylenically unsaturated bond can also be used, and is not limited to a specific one, but in particular, any of the resins listed below (oligomers and polymers) May be used suitably.

As the carboxyl group-containing resin (B),
(1) a carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid and a compound having an unsaturated double bond,
(2) An epoxy group of a copolymer of a compound having an epoxy group and an unsaturated double bond and a compound having an unsaturated double bond has one carboxyl group in one molecule, and has an ethylenically unsaturated bond. It is obtained by reacting a polybasic acid anhydride with a secondary hydroxyl group produced by reacting an organic acid that does not have, and (3) reacting the polybasic acid anhydride with a hydroxyl group-containing polymer. Examples include carboxyl group-containing resins.

In addition, as the carboxyl group-containing photosensitive resin (B ′),
(1) A carboxyl group-containing photosensitive resin obtained by partially adding an ethylenically unsaturated group as a pendant to a carboxyl group of a copolymer of a compound having an unsaturated carboxylic acid and an unsaturated double bond,
(2) An epoxy group of a copolymer of an epoxy group and a compound having an unsaturated double bond and a compound having an unsaturated double bond is reacted with an unsaturated carboxylic acid, and the resulting secondary hydroxyl group is converted to a polybasic acid. A carboxyl group-containing photosensitive resin obtained by reacting an anhydride,
(3) A carboxyl group-containing photosensitive resin obtained by reacting a copolymer of an acid anhydride having an unsaturated double bond and a compound having an unsaturated double bond with a compound having a hydroxyl group and an unsaturated double bond. ,
(4) a carboxyl group-containing photosensitive resin obtained by reacting a polyfunctional epoxy compound with an unsaturated monocarboxylic acid and reacting the resulting secondary hydroxyl group with a polybasic acid anhydride, and (5) a hydroxyl group-containing polymer. Examples thereof include a carboxyl group-containing photosensitive resin obtained by further reacting a compound having an epoxy group and an unsaturated double bond with a carboxyl group-containing resin obtained by reacting a polybasic acid anhydride.

  The carboxyl group-containing resin (B) and the carboxyl group-containing photosensitive resin (B ′) have a weight average molecular weight of 1,000 to 100,000, preferably 5,000 to 70,000, and an acid value of 20 It is -250 mgKOH / g, Preferably it is 50-150 mgKOH / g. In the case of the carboxyl group-containing photosensitive resin (B ′), those having a double bond equivalent of 350 to 2,000, preferably 400 to 1,500 can be suitably used. When the molecular weight of the resin is lower than 1,000, the adhesion of the film during development is adversely affected. On the other hand, when the molecular weight is higher than 100,000, development defects are liable to occur. On the other hand, when the acid value is lower than 20 mgKOH / g, the solubility in an alkaline aqueous solution is insufficient, and development failure tends to occur. On the other hand, when the acid value is higher than 250 mgKOH / g, the adhesion of the film is deteriorated during development and the photocured part (exposure) Part) is not preferable. Further, in the case of a carboxyl group-containing photosensitive resin, if the double bond equivalent of the photosensitive resin is less than 350, a residue is likely to remain at the time of baking, whereas if it is greater than 2,000, a work margin at the time of development. Is narrow, and a high exposure amount is required at the time of photocuring.

  Such a carboxyl group-containing resin (B) and a carboxyl group-containing photosensitive resin (B ′) may be used alone or in combination, but in any case, they are 10 to 80 of the total amount of the composition. It is preferable to mix | blend in the ratio of the mass%. When the blending amount of these resins is less than the above range, the distribution of the resin in the film to be formed tends to be non-uniform, especially in the case of a carboxyl group-containing photosensitive resin, sufficient photocurability and photocuring depth. Is difficult to obtain, and patterning by selective exposure and development becomes difficult. On the other hand, if it is more than the above range, it is not preferable because the pattern during baking and the shrinkage of the line width are likely to occur.

  Examples of the photopolymerizable monomer (C) include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, polyurethane diacrylate, trimethylolpropane triacrylate, Pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane ethylene oxide modified triacrylate, trimethylolpropane propylene oxide modified triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and each methacrylate corresponding to the above acrylate; phthalate Acid, adipic acid, maleic acid, Mono-, di-, tri- or higher polyesters of polybasic acids such as conic acid, succinic acid, trimellitic acid and terephthalic acid and hydroxyalkyl acrylate or hydroxyalkyl methacrylate, etc. It is not limited and these can be used alone or in combination of two or more. Among these photopolymerizable monomers (C), polyfunctional monomers having two or more acryloyl groups or methacryloyl groups in one molecule are preferable.

  The amount of such photopolymerizable monomer (C) is suitably 20 to 100 parts by mass per 100 parts by mass of the carboxyl group-containing resin (B) and / or carboxyl group-containing photosensitive resin (B ′). . When the blending amount of the photopolymerizable monomer (C) is less than the above range, it is difficult to obtain sufficient photocurability of the composition. On the other hand, when the amount exceeds the above range, the surface is larger than the deep part of the film. Uneven curing is likely to occur because the photocuring of the part is accelerated.

  Specific examples of the photopolymerization initiator (D) include benzoin and benzoin alkyl ethers such as benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2, Acetophenones such as 2-diethoxy-2-phenylacetophenone and 1,1-dichloroacetophenone; 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2- Aminoacetophenones such as dimethylamino-1- (4-morpholinophenyl) -butanone-1; anthraquinones such as 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 1-chloroanthraquinone; 2 Thioxanthones such as 4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, and 2,4-diisopropylthioxanthone; Ketals such as acetophenone dimethyl ketal and benzyldimethyl ketal; Benzophenones such as benzophenone; or xanthones; (2,6-dimethoxybenzoyl) -2,4,4-pentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl Phosphine oxides such as -2,4,6-trimethylbenzoylphenyl phosphinate; various peroxides and the like, and these known and commonly used photopolymerization initiators may be used alone or in combination of two or more. In combination it can be used.

The photopolymerization initiator (D) is composed of N, N-dimethylaminobenzoic acid ethyl ester, N, N-dimethylaminobenzoic acid isoamyl ester, pentyl-4-dimethylaminobenzoate, triethylamine, triethanolamine. It can be used in combination with one or more photosensitizers such as tertiary amines.
The blending ratio of these photopolymerization initiator (D) and photosensitizer is 1 to 30 parts by mass per 100 parts by mass of the carboxyl group-containing resin (B) and / or carboxyl group-containing photosensitive resin (B ′). Is suitable, and preferably 5 to 20 parts by mass.

The fine powder boric acid (E), which is the first feature of the present invention, has an average particle size (D ₅₀ ) of 20 μm or less, preferably 5 μm or less, finely pulverized by a jet mill, ball mill, roll mill or the like. The finely powdered product is likely to absorb moisture and re-aggregate, so that it is preferably used immediately after pulverization. Moreover, it can also grind | pulverize with resin, a solvent, etc. which are contained in a paste.
The blending ratio of boric acid (E) having an average particle size (D ₅₀ ) of 20 μm or less is suitably 0.01 to 10 parts by weight per 100 parts by weight of inorganic fine particles (A) excluding boric acid, preferably 0.1 to 2 parts by mass.

The photosensitive paste of the present invention becomes a paste by diluting the composition with an organic solvent, and can be easily applied. In addition, an appropriate amount of an organic solvent can be blended in order to form a film by drying and enable contact exposure. However, when water is contained in the organic solvent, metal ions are eluted from the inorganic fine particles (A) excluding the boric acid, and gelation is promoted. Therefore, the second feature of the present invention is that the hydrophobic solvent (F) is used.
The hydrophobic solvent (F) referred to in the present invention is a solvent that does not mix freely with water but separates, and preferably has a solubility in 100 g of water at 25 ° C. of 20 g or less, and more preferably has a solubility of 20 g or less. 10 g or less of organic solvent.
Examples of the hydrophobic solvent (F) of the present invention include acetates such as propylene glycol methyl ether acetate and dipropylene glycol methyl ether acetate, glycol ethers such as propylene glycol phenyl ether, and ketones such as methyl ethyl ketone and cyclohexanone; Aromatic hydrocarbons such as toluene, xylene and tetramethylbenzene; aliphatic hydrocarbons such as octane and decane; petroleum solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha and solvent naphtha, and 2,2,4 -Alcohols such as trimethyl-1,3-pentanediol monoisobutyrate and terpionele are mentioned, and these can be used alone or in combination of two or more.
The hydrophobic solvent (F) can be used only when preparing a photosensitive paste, and then supplied as a green sheet applied and dried on a carrier film.
Further, if necessary, a hydrophilic solvent can be used in combination. In that case, the amount of the hydrophobic solvent in the total solvent is preferably 30% by mass or more. Examples of such hydrophilic solvents include propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, and the like.

The photosensitive paste of the present invention can contain a polyhydric alcohol (G) in order to improve the storage stability of the composition. These polyhydric alcohols (G) have the effect of increasing the acidity of boric acid (E) having an average particle size (D ₅₀ ) of 20 μm or less, and the gelation speed is increased depending on the molecular weight, acid value, etc. of the carboxyl group-containing resin. Effectively improves storage stability when used in fast resins.
Examples of such a polyhydric alcohol (G) include mannitol, sorbitol, dextrin, fructose glycerin, etc. Among them, D (−)-mannitol having a low hygroscopic property is preferable.
The blending amount of the polyhydric alcohol (G) is suitably 0.01 to 10 parts by mass with respect to 1 part by mass of boric acid (E) having an average particle size (D ₅₀ ) of 20 μm or less, preferably 0. .5 to 2 parts by mass.

  If necessary, the photosensitive paste of the present invention may further contain other additives such as a defoaming / leveling agent such as silicone and acrylic, and a silane coupling agent for improving the adhesion of the film. You can also. Furthermore, if necessary, fine particles such as metal oxides, silicon oxides, boron oxides, and the like, which are known and commonly used antioxidants, and as binding components to the substrate during firing may be added.

  The photosensitive paste of the present invention as described above may be laminated on a substrate when it is previously formed into a film, but in the case of a paste, a screen printing method, a bar coater, a blade coater For example, about 60 to 120 ° C. in a hot-air circulating drying furnace or a far-infrared drying furnace in order to apply to a substrate, for example, a glass substrate serving as a front substrate of a PDP by a suitable coating method. The organic solvent is evaporated by drying for about 5 to 40 minutes to obtain a tack-free coating film. Thereafter, selective exposure, development, and firing are performed to form a predetermined fired product pattern.

The selective exposure can be contact exposure and non-contact exposure using a negative mask having a predetermined exposure pattern. As the exposure light source, a halogen lamp, a high-pressure mercury lamp, a laser beam, a metal halide lamp, a black lamp, an electrodeless lamp, or the like is used. The exposure amount is preferably about 50 to 1000 mJ / cm ² .

  For the development, a spray method, a dipping method or the like is used. Developers include aqueous alkali metal solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and sodium silicate, and aqueous amine solutions such as monoethanolamine, diethanolamine and triethanolamine, especially about 1.5% by mass or less. A dilute alkaline aqueous solution having a concentration of 1 is preferably used, as long as the carboxyl group of the carboxyl group-containing resin in the composition is saponified and the uncured part (unexposed part) is removed. It is not limited to. Further, it is preferable to perform washing with water and acid neutralization in order to remove unnecessary developer after development.

  The substrate patterned by the above development can be fired at about 400 to 600 ° C. in air or in a nitrogen atmosphere to form a desired fired product pattern. In addition, it is preferable to set the temperature increase rate at this time to 20 degrees C / min or less.

  In addition, an inorganic fine particle (A) component can be suitably selected according to the kind of desired baked material pattern. For example, in the case of forming an electrode pattern, a conductive powder is used, but it is preferable to use an appropriate amount of glass fine particles in combination in order to improve the firing property. In particular, when forming a black electrode pattern, a black pigment is also used. In the case of a black matrix pattern, glass fine particles and black pigment are used, and glass fine particles are used to form the partition pattern.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples. “Parts” and “%” are based on mass unless otherwise specified.

<Materials used in Examples and Comparative Examples>
A carboxyl group-containing resin (B-1) composed of methyl methacrylate (MMA) and methyl acrylate (MA) having a weight average molecular weight of about 10,000 and an acid value of 60 mgKOH / g, a weight average molecular weight of about 50,000, and an acid value Was blended at a composition ratio shown in the following table using a carboxyl group-containing resin (B-2) composed of MMA and MA of 120 mgKOH / g, and stirred and adjusted with a stirrer.
The photopolymerizable monomer (C) uses trimethylolpropane trimethacrylate (TMPTMA), and the photopolymerization initiator (D) is 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholinophenyl). ) Butanone (Irgacure 379, manufactured by Ciba Specialty Chemicals) was used.
As the solvent, dipropylene glycol methyl ether acetate (DPMA, manufactured by Dow Chemical Company) and Solvesso # 200 (ExxonMobil Chemical Company) were used as the hydrophobic solvent (F), and tripropylene glycol methyl was used as the hydrophilic solvent of the comparative example. Ether (TPM, manufactured by Dow Chemical Company) was used.
As for boric acid, a commercially available product (manufactured by Kanto Chemical Co., Inc.) boric acid powder (D1) having an average particle size of 790 μm was pulverized by a jet mill, boric acid (D2) having an average particle size of 20 μm, and an average particle size of 1.7 μm (D3). ) Was obtained.
In addition, the measuring method of a particle diameter is a laser method, and a measuring apparatus is Mastersizer 2000 (dry type).
Furthermore, as the glass powder, PbO 60%, B ₂ 0 ₃ 20%, SiO ₂ 15%, Al ₂ 0 ₃ 5% were pulverized, thermal expansion coefficient α ₃₀₀ = 70 × 10 ⁻⁷ / ° C., glass transition point What set it as 445 degreeC and the average particle diameter of 1.6 micrometers was used. Silicone oil KS-66 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added as an additive.

Examples 1-6
The components shown in Table 1 below were blended in the composition ratios shown in the table, stirred with a stirrer, and then kneaded with a three-roll mill to obtain a photosensitive paste.

Comparative Examples 1-9
The components shown in Table 2 below were blended in the composition ratios shown in the table, stirred with a stirrer, and then kneaded with a three-roll mill to obtain a photosensitive paste.

  For each of the pastes of Examples 1 to 6 and Comparative Examples 1 to 9 thus obtained, the viscosity immediately after creation, the viscosity after storage for 1 week at 25 ° C., and the viscosity after storage for 1 month at 25 ° C. were measured, respectively. The rate of increase from the immediate viscosity was calculated. These evaluation results are shown in Table 3 below.

Developability: Each paste of Examples 1 to 6 and Comparative Examples 1 to 9 after storage at 25 ° C for 1 month was examined for developability by the following method.
(Evaluation Substrate) The substrate used for this evaluation was coated on the entire surface of an ITO film-coated glass substrate using a 300-mesh polyester screen, and then heated at 90 ° C. in a hot air circulating drying oven. The film was dried for 5 minutes to form a film having good dryness to the touch. Thereafter, a metal halide lamp was used as the light source, and exposure was performed using a striped negative mask having a line width of 10 to 100 μm and a space width of 100 μm so that the integrated light amount on the composition was 100 mJ / cm ² . Development was performed for 30 seconds using a 0.5 wt% aqueous solution of Na ₂ CO ₃ and washed with water.
(Evaluation Method) The line shape after development was evaluated by observing the pattern that had been completed up to development under a microscope, and whether there was no irregular variation in the line and there was no development residue. These evaluation results are shown in Table 3 below.
The evaluation criteria for the line shape are as follows.
○: There is no irregular variation and there is no development residue.
Δ: Irregular variation, development residue, etc.
X: Development is impossible.

As is clear from the results shown in Table 3, it can be seen that the photosensitive pastes of the present invention of Examples 1 to 6 are superior in storage stability as compared with the photosensitive pastes of Comparative Examples. For example, Comparative Example 1 using only a hydrophilic solvent is gelled after 25 months at 25 ° C., and thickening of Comparative Examples 2 and 3 using boric acid having an average particle size (D ₅₀ ) exceeding 20 μm. It can be seen that the rate is large compared to the example.
Moreover, it turns out that Example 5 which added the polyhydric alcohol is improving the storage stability compared with Example 4 which is not added.

It is a partial exploded perspective view of a surface discharge AC type PDP.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front glass substrate 2a, 2b Display electrode 3, 3a, 3b Transparent electrode 4, 4a, 4b Bus electrode 5 Transparent dielectric layer 6 Protective layer 10 Black matrix 11 Back glass substrate 12 Rib 13 Address electrode 14a, 14b, 14c Fluorescence

Claims (4)

(A) inorganic particles excluding boric acid, (B) a carboxyl group-containing resin, (C) photopolymerizable monomer, (D) a photopolymerization initiator, (E) The average particle size _(D 50) 20 [mu] m or less of boric acid and, ( F) A photosensitive paste containing a hydrophobic solvent. Furthermore, (G) polyhydric alcohol is contained, The photosensitive paste of Claim 1 characterized by the above-mentioned. The photosensitive paste according to claim 1 or 2, wherein the inorganic fine particles (A) excluding boric acid are at least one selected from the group consisting of glass fine particles, black pigments, and conductive powders. The pattern obtained using the photosensitive paste according to any one of claims 1 to 3 is selected from the group consisting of a partition pattern, a dielectric pattern, an electrode pattern, and a black matrix pattern of a flat panel display. A fired product pattern, which is at least one kind.